Conventionally, various kinds of print systems which perform a print process to a document to which authenticity should be certified are proposed as follows.
For example, in Japanese Patent Application Laid-Open No. 2000-285024, to cause electronic information to have a property of a paper original and thus increase probative force of the electronic information, in a case where electronic data is stored, a file attribute code indicating that the electronic data in question corresponds to the original is added, and the electronic data to which the file attribute code has been added is stored in a state distinguishable from at least other electronic data.
Further, in Japanese Patent Application Laid-Open No. 2001-202436, to ensure security of a stored written application document for a long period of time, an electronic application system in which an application of an electronic document is performed from a terminal through a network. Here, the electronic application system consists of a document storage apparatus, a calculation means for calculating alteration detection code from information including the document transmitted from the terminal, and a storage means for storing the information and the alteration detection code in the document storage apparatus.
Furthermore, in Japanese Patent Application Laid-Open No. 2000-224407 filed by the applicant of the present application, to improve reliability of printing concerning a digital signature, a message digest value is added to a print in a form by which alteration is difficult, whereby the value of document data to which the digital signature has been appended can be improved.
Moreover, as shown in Japanese Patent Application Laid-Open Nos. 2000-285024 and 2001-202436, when the former data is stored in an administration server as of electronic information, a large-scale electronic storage apparatus is necessary, whereby it is not easy to maintain and administrate the storage apparatus. Besides, because the electronic information is stored in the external storage apparatus for a long period of time, a risk that secret information is leaked increases.
Furthermore, although Japanese Patent Application Laid-Open No. 2000-224407 filed by the applicant proposes the method to increase the reliability of printing concerning the digital signature, it is not disclosed even in this case that a third party certifies the date and hour when the printing is performed and the contents of the print obtained in the printing.
Incidentally, in such conventional print systems as described above, it is necessary to store a great deal of information so that a printed material is obtained as it is certified that the obtained printed material corresponds to the original. For this reason, a large storage capacity is required in the storage apparatus to certify one data, whereby a serious and significant administration load is imposed to the system for keeping a secret of the stored electronic data.